Experimental study of quark gluon plasma with single photon measurement

夸克胶子等离子体单光子测量实验研究

• 批准号: 11440075
• 负责人: HAMAGAKI Hideki
• 金额: $ 9.73万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11440075/
• 关键词: RHIC; PHENIX; quark gluon plasma; calorimeter; pion; single photon; jet energy loss; クォーク・グルオン・プラズマ; パイ中間子; PHENIX; カロリメーター

In the summer of 2000, collisions between Au nuclei were realized at RHIC, and experimental studies have started. This project aims to confirm the realization of quark gluon plasma (QGP), and to study the properties of QGP, in the PHENIX experiment at RHIC. Primary device was a electro-magnetic calorimeter, in order to measure photons emitted from the collisions between 65 AGeV Au nuclei. With photon measurements, neutral pion yield and spectra would be determined and ultimate goal was to deduce single-photon yield. Analysis frame was constructed, which consists of PC's connected via high-speed network and RAID disks.Neutral pions with high pT are mainly produced as a residue of jets which are produced with the scattering between partons. Jet will suffer large energy loss due to strong interactions when it passes through the matter at high temperature in the initial stage of collisions. The result provided the first evidence of the jet energy-loss.Single photon is a probe of QGP, which directly provides information from the QGP. Large photon yield is predicted in the theory, which assumes fast thermalisation due to gluon contributions. Large enhancement in the photon yield was not observed in this study, which places strong restriction to the models.

2000年夏天，在RHIC上实现了Au核之间的碰撞，并开始了实验研究。本计画旨在确认在RHIC的PHENIX实验中夸克胶子电浆（QGP）的实作，并研究QGP的性质。主要设备是电磁量热计，以测量从65 AGeV Au核之间的碰撞发射的光子。通过光子测量，可以确定中性π介子产额和光谱，最终目标是推导单光子产额。构造了由高速网络连接的PC机和RAID磁盘组成的分析框架，高pT中性π介子主要是由部分子间散射产生的喷注的残余物产生的。在碰撞的初始阶段，由于强相互作用，射流在穿过高温物质时会损失大量的能量。单光子是QGP的探针，直接提供QGP的信息。大的光子产额预测的理论，假设快速热化由于胶子的贡献。在本研究中没有观察到光子产额的大幅增强，这对模型有很大的限制。

项目成果

L.Ahle: "Proton and deuteron production in Au+Au reactions at 11.6/A-GeV"Physical Review C. 60. 064901-1-16 (1999)

L.Ahle：“11.6/A-GeV 下 Au Au 反应中的质子和氘核产生”物理评论 C. 60. 064901-1-16 (1999)

T.Abott他(BNL-AGSF802 Collaboraion): "Systematics of Midropidity Transverse Energy Distributional in Limited Aperturec from p + Be to Au + Ay Cikksabt at Related Ene A"Phys. Rev. C. 63. 064602 (2001)

T. Abott 等人（BNL-AGSF802 合作）：“相关 Ene A 中从 p + Be 到 Au + Ay Cikksabt 的 Midropidity 横向能量分布的系统学”Phys。

L.Ahle: "Excitation Function of K^+ and π^+ Production in Au+Au Reactions at 2/A-GeV to 10/A-GeV"Physics Letters. B476. 1-8 (2000)

L.Ahle：“2/A-GeV 至 10/A-GeV 下 Au+Au 反应中 K^+ 和 π^+ 生成的激发函数”《物理快报》B476。

L.Ahle: "Centrality dependence of kaon yields in Si+A and Au+Au collisions at relativistic energies"PHYSICAL REVIEW C. 60. 044904-1-044904-11 (1999)

L.Ahle：“相对论能量下 Si A 和 Au Au 碰撞中 kaon 产率的中心依赖性”物理评论 C. 60. 044904-1-044904-11 (1999)

L.Ahle他: "An Excitation Function of K^-and K^+ production in Au + Au Reactions at the AGS"Phys. Lett.. B490. 53-60 (2000)

L.Ahle 等人：“AGS 中 Au + Au 反应中 K^- 和 K^+ 生成的激发函数”Phys. B490 (2000)。